Vista on good equipment with plenty RAM simply isn't slower than XP. The benchmarks are all over the place comparing the two but when it comes to games the frame rates are equalized and in other things this seems to be the case too.
Aero transfers the heavy lifting of the grapichal interface from your CPU and system RAM to the graphics card which has plenty to spare when not running 3d apps/games. It may actually speed up the sustem to leave it ON.
Vista has a somewhat higher RAM print than XP, as you would expect from an OS written for modern systems with oodles of RAM compared to the XP spec which started at about 128 meg and even ran on less.
But the main reason Vista will consume your RAM is superfetch - the aggressive pre-loading of frequently used code into RAM so that your most used apps will start much faster.
I have 8 gig if ram on my Vista 64 system and when only surfing almost half of it is being used. This is NOT Vista bloat, this is superfetch, and in my experience it helps a lot as my favorite apps load instantly.
If you go 32bit, you only get to use 3GB of that ram you're going to install (not enough addressing space) I really would suggest going with Vista 64.
What are you going to be using the system for and what will the rest of the components be?
All that being said, you shouldn't notice any difference with a 2.93GHz Nehalem, from the early signs it looks like it's going to be a beastly processor, even on my E8400 Vista is blazing quick.
Don't you need to get a 64-bit version of every program you use? Or can you still use 32-bit programs without switching settings?
Edit: This is going to be a gaming rig. Going to need to get an X58 mobo; I'll probably go with Asus. Planning on throwing in an evga GTX 280 SSC, Sound Blaster Fatal1ty Xtremegamer X-Fi Pro sound card, Velociraptor x1, Corsair 750W non-modular/single rail PSU, OCZ 4GB DDR3 1600 RAM at (I think) 7-6-6-24.
Nope, you don’t need all 64-bit applications to run them on Vista 64. It’s got a 32-bit shell, or emulator that gets the job done fine. I’ve been running Vista 64 for about a year now and I still haven’t found a program that won’t run on it, be it games, photo editing or document creation and management. And most of my games and applications are 32 bit.
Geo - I used to think that myself, until I educated myself a little more. The truth of the matter is far more elegant:
Since x64 is a superset of x86, current processors don't care whether the binaries are 32 or 64 bit. The CPU is simply running the instructions presented to it. The WOW64 service in XP 64 and Vista 64 does the required file location and registry redirections. But otherwise, the binaries run untouched, and as originally intended, with no translation layer. What matters is the app developers use the proper API's when they programmed the thing.
What this means is that your 32 bit apps run perfectly well on current 64 bit windows operating systems.
Microsoft Windows XP Service Pack 3 (SP3) since 2001, including the Windows XP release date all the patches, also includes a small number of new features. SP3 installed XP SP2 does not want to change significantly as the user experience.
I was not very clear, I do not know who knows, you can click on software outsourcing